I've answered a few different questions about this topic which you may find useful.

• Were the wives of enslavers jealous of their husband's actions with enslaved women?
• Where did Jefferson have sex with his slaves?

One thing I do want to clarify is that it's misleading to suggest enslavers and the women and girls they enslaved had relationships that were maintained in the way we may think of it today. Regarding Jefferson, we really do not have a good understanding what transpired between him and Sally Hemmings as she left no written word behind for us to read.

From my answer on Jefferson:

One of the best primary sources we have related to the lived experiences of enslaved people are the interviews conducted for the Works Progress Administration (WPA) in the 1930's of people who had been enslaved. Historians, including Clinton and others, have highlighted that the nature of the interviews may have limited respondents' answers about sexual assault and rape and unfortunately, we have a weak understanding of the when and where of assaults. One interviewee, however, reported3:

I was regarded as fair-looking for one of my race, and for four years a white man— I spare the world his name— had base designs upon me. I do not care to dwell upon this subject, for it is one that is fraught with pain. Suffice it to say that he persecuted me for four years, and I— I— became a mother. The child of which he was the father was the only child that I ever brought into the world. If my poor boy ever suffered any humiliating pangs on account of the birth, he could not blame his mother, for God knows that she did not wish to give him life; he must blame the edicts of that society which deemed it no crime to undermine the virtue of girls in my then position.